An apparatus for treating fluorine-containing wastewater includes a first reactor configured to be injected with a water-soluble calcium salt and fluorine-containing wastewater to produce a water-insoluble calcium salt; a second reactor configured to be injected with a first effluent from the first reactor, a water-soluble aluminium salt and carbonated water to produce a water-insoluble aluminium salt; a third reactor configured to be injected with a second effluent from the second reactor and a polymer coagulant to coagulate the water-insoluble calcium salt and the water-insoluble aluminium salt mediated by the polymer coagulant; and a sedimentator configured to be injected with a third effluent from the third reactor and to sediment the water-insoluble aluminium salt and the water-insoluble calcium salt coagulated in the third effluent by solid-liquid separating the third effluent.

Provided is a filtration aid used when filtering, for example, sludge generated in a purification treatment process for water such as industrial wastewater and including a pulverized product of Corchorus olitorius, wherein a median diameter of the pulverized product is 150 micrometers or greater.

Provided is a water-purifying agent formed of a granulated product including a mixture of a plant powder and a polymeric flocculant, wherein a surface of the granulated product includes a coated portion in which the plant powder is coated with the polymeric flocculant and a non-coated portion in which the plant powder is not coated with the polymeric flocculant.

The present disclosure relates to water purification compositions and the method of producing the same. Specifically, the present disclosure relates to a method of producing a water purification composition including providing a substrate having one or more functional groups that has hydroxyl, thiol, carboxyl, and/or amino group; depositing a solution of a metal salt on the substrate; depositing a solution of carboxylic acid compound on the substrate; forming a mixture wherein the metal cross-links the hydroxyl, thiol, carboxyl and/or amino groups on the surface of the substrate, and the carboxylic acid compound; and heating the mixture till the product is dry.

Provided are an extract, which is a fractionated component 1 of a water extract of a plant powder, wherein the fractionated component 1 is a fractionated component having a fractionation molecular weight of 12,000 or greater, wherein an ethanol-undissolved component of the fractionated component 1 exhibits a peak attributable to carboxylic acid in a Fourier transform infrared spectroscopy (FT-IR) measurement and exhibits a peak attributable to cellulose in a gas chromatography mass spectrometry (GC-MS) measurement, and wherein an ethanol-dissolved component of the fractionated component 1 exhibits a peak attributable to carboxylic acid in the FT-IR measurement and exhibits a peak attributable to a plant protein in the GC-MS measurement, and a water-purifying agent containing the extract.

A method of treating a waste liquid: an aluminum dissolution step of dissolving aluminum in an acidic waste liquid and performing separation into a first treated water and a reduced heavy metal precipitate; a gypsum recovery step of adding a calcium compound to the first treated water at a pH of 4 or less, and performing separation into a second treated water and gypsum; a heavy metal coprecipitation step of adding a ferric compound to the second treated water and performing separation into a third treated water and a heavy metal coprecipitate; an aluminum and fluorine removal step of adding an alkali to the third treated water and performing separation into a fourth treated water and a precipitate containing aluminum and fluorine; and a neutralization step of adding an alkali to the fourth treated water and performing separation into an alkali neutralization treated water and a neutralized heavy metal hydroxide.

Provided are electrodialysis systems comprising a plurality of electrodialysis devices, wherein each electrodialysis device of the plurality of electrodialysis devices has a product inlet stream, a product outlet stream, a brine inlet stream, and a brine outlet stream. The product inlet stream for a first electrodialysis device comprises the brine outlet stream of a second electrodialysis device. Further, a first portion of a feed stream is the brine inlet stream for the first electrodialysis device and a second portion of the feed stream is the brine inlet stream for the second electrodialysis device or a third electrodialysis device.

The invention relates to a method for treating fluoride-containing, in particular HF containing wastewater to remove fluoride and to a corresponding apparatus. In the new method calcium carbonate is reacted in a reaction step at an acidic pH4 with the fluoride in the wastewater to form calcium fluoride particles. Then, in a subsequent filtration step said calcium fluoride particles are separated by a porous membrane from the treated wastewater. The inventive apparatus comprises at least one reaction container/tank for reacting calcium carbonate at an acidic pH4 with fluoride in the wastewater to form calcium fluoride particles, as well as at least one porous membrane, in particular at least one porous ceramic membrane for separating calcium fluoride particles from the treated wastewater in a filtration step.

The invention provides a water filtration system for removing heavy metals, residual chlorine, estrogens, bacteria and dust from tap water. The system includes a first adsorbent stage cartridge including approximately 40-65 wt. % of silver-impregnated activated carbon, approximately 1-10 wt. % of activated alumina, approximately 15-35 wt. % of ceramic balls, approximately 0.5-1 wt. % of chitosan and approximately 0.5-1 wt. % of kinetic degradation fluxion media. The second filtration stage cartridge includes an antifouling electrospun nanofiber membrane. A flow path is provided between the first adsorbent stage cartridge and the second filtration stage cartridge. The multiple stage water filtration system is capable of filtering water at a volume rate of at least approximately 2 liters per minute. In one embodiment, the nanofibers may be polyvinylidene fluoride doped with polyacrylonitrile and including bacteria-repellent methoxy polyethylene glycol side chains such that the nanofiber membrane has a water contact angle of approximately 55 degrees or less.

A method to prepare a coated current collector electrode of a flow through capacitor. The method includes preparing a coating paste includes: 10-50 weight % of carbon having a specific surface area of at least 500 m.sup.2/g; 0.3-5 weight % of a binder; 10-50 weight % based on the total paste of a first solvent having a first boiling point; and 10-50 weight % based on the total paste of a second solvent having a second boiling point. The method further includes applying the coating paste on a current collector; and allowing the second solvent in the coating paste applied on the current collector to evaporate at a temperature lower than the first boiling point.